Known lever door handles or knobs operate by turning the handle on the door which removes a latch from a recess in the door jamb. While sometimes these lever handles have locks, the locks are frequently automatically unlocked when the door handle is rotated from the interior side of the door (i.e. inside of the building or room). Thus, the only way to prevent unlocking and opening of the door by a small child is to prevent turning of the door handle.
One such safety device, offered by G2 Products of Franklin, Wis., has a collar and clip that fit over a lever door handle located close to a door jamb. The collar has two arms that extend radially relative to the axis of rotation of the handle. When a child attempts to rotate the handle, the arms collide with the door jamb preventing rotation of the door handle. This design, however, does not work with French or double doors where no door jamb is positioned close to the door handle.
In addition, this type of safety lock will only provide entry from the opposite side of the door when opposing lever door handles on the same door operate independently. For door handles on the opposite sides of a door that must rotate simultaneously in order to open the door, this kind of safety lock will prevent entry from both sides of the door. With such a door handle arrangement, turning the lever handle from the outside of the door would also turn the lever handle on the inside of the door and, as a result, the lock would be broken if an individual forced the handle to turn so as to gain entry.
Furthermore, this type of lock must be manually reset every time an individual passes through the door. This may be problematic in that some individuals, such as visitors or older children, may forget to reset the lock.
Another known child safety door lock, offered by Safety 1st of Canton, Mass., includes a collar that is mounted to the door and fits around the axial shank of the lever door handle. This design has a spring loaded button that is placed along the circumference of the collar and biased outward from the collar and door surface. The button blocks the rotational pathway of the lever door handle so that the handle cannot be rotated unless the button is depressed and slid on the collar away from the handle. The device features an override, however, that permits the door handle to be turned, even when the lock is activated, if a turning force of over approximately five kilograms is applied. This level of force is believed to be greater than what a young child could provide and permits entry into the room from the opposite side of the door by adults and older children.
A disadvantage of this lock, however, is that the door handle mechanism must be disassembled to install the product. In addition, this type of lock also must be manually reset every time an individual passes through the door.
Another child safety door lock on the market is the LEVER LOK product offered by Mommy's Helper, Inc. of Witchita, Kans. This product features a bowl-shaped cover or shield that is mounted on the door and surrounds the sides and bottom of a door lever handle. As a result, the door lever handle may only be activated by reaching down through the open top of the cover. This prevents young children from accessing the door lever handle due to their limited reach. A disadvantage of this arrangement, however, is that the door latch plate must be disassembled for the product to be installed. In addition, the effectiveness of the product is limited by the height of the door lever handle.
Accordingly, it is an object of the present invention to provide a child safety lock for lever door handles.
It is another object of the present invention to provide a child safety lock that permits a door to be locked on one side while unlocked on the other side.
It is another object of the present invention to provide a child safety lock that automatically resets.
It is still another object of the present invention to provide a child safety lock for a door handle that may be installed without disassembling the door handle.
These and other objects and advantages will be apparent from the following specification.